Suturing of tissue during surgical procedures is time consuming and can be particularly challenging in difficult to access body regions and regions that have limited clearance, such as regions partially surrounded or covered by bone. For many surgical procedures, it is necessary to make a large opening in the human body to expose the area requiring surgical repair. However, in many cases, accessing the tissue in this manner is undesirable, increasing recovery time, and exposing the patient to greater risk of infection.
Suturing instruments (“suture passers” or “suturing devices”) have been developed to assist in accessing and treating internal body regions, and to generally assist a physician in repairing tissue. Although many such devices are available for endoscopic and/or percutaneous use, these devices suffer from a variety of problems, including limited ability to navigate and be operated within the tight confines of the body, risk of injury to adjacent structures, problems controlling the position and/or condition of the tissue before, during, and after passing the suture, as well as problems with the reliable functioning of the suture passer.
For example, some surgical instruments used in endoscopic procedures are limited by the manner in which they access the areas of the human body in need of repair. In particular, the instruments may not be able to access tissue or organs located deep within the body or that are in some way obstructed. In addition, many of the instruments are limited by the way they grasp tissue, apply a suture, or recapture the needle and suture. Furthermore, many of the instruments are complicated and expensive to use due to the numerous parts and/or subassemblies required to make them function properly. Suturing remains a delicate and time-consuming aspect of most surgeries, including those performed endoscopically.
During or after performance of a surgical procedure, tissues must be stitched or sutured to allow or encourage healing. Suturing, that is, the tying a tissue with a suture (e.g., thread), is well-known in the art. Moreover, pre-tied sutures and methods of suturing for external surgical use likewise are known, such as is described in U.S. Pat. No. 3,580,256 to Wilkinson et al. The Wilkinson patent describes a pre-tied suture that is encased in a see-through material, taking the form of a thin, flat wafer. In use, the surgeon stitches the tissue together and then directs the needle through the loops in the wafer and draws it tight in order to make the knot. Clearly, such a convention could not be used for endoscopic and other internal surgical techniques.
In contrast, minimally invasive surgery, such as endoscopic surgery, is performed within the interior of a body, including a body cavity or hollow organ, with the help of an endoscope or similar device to visualize the interior portions of the body where the surgery is to be performed. Small, low-profile or compact devices, such as suture passers, may be used to pass a suture through the tissue, and subsequently tie off the suture. The surgeon may observe the surgical procedure through a visual device whose output is displayed on a video monitor.
In order to perform the suturing within patient's body, a suture passer with a tissue penetrator (e.g., needle) element may pass through the tissue one or more times (including through a tissue and a non-tissue material, such as an implant, graft, etc.). The tissue penetrator may pass a suture directly, or it may pass an element that can later pull a suture through the tissue. A problem may arise in manipulating the tissue penetrator (e.g., needle) for easily tying a knot for closing the surgical incision in situ. It is challenging to tie off or otherwise secure the free end or ends of a suture, particularly minimally invasively. Thus, it is to be appreciated that a pre-tied suture, employable with a suture passer or grasping instrument, could greatly facilitate minimally invasive and other surgical procedures (even including open procedures). The present invention is directed to such methods and systems for knotting suture that allow a pre-tied knot to be present, pre-attached or pre-tied onto the suture before performing the surgical procedure.
It is also desirable to suture tissue using a suture passer that can reliably transfer a suture through the tissue without dropping the suture. Described herein are suture passers and methods of passing sutures that enhance reliability by passing a suture that is pre-knotted or otherwise includes an enlarged region on the suture (e.g., near the end region of a suture) to reliably pass the suture (including the knot) through the tissue.